lvm and hardware raid? - Setup

This is a discussion on lvm and hardware raid? - Setup ; Is there any reason to use lvm on a server with a hardware raid controller?
Wouldn't using lvm be redundant and introduce additional overhead?
Rhel 4.4 installed lvm by default, even though the system is installed on a
hardware raid ...

Re: lvm and hardware raid?

frank wrote:
> Is there any reason to use lvm on a server with a hardware raid controller?
> Wouldn't using lvm be redundant and introduce additional overhead?

Uh.. yes... of course.

And no... the overhead is minimal. While it is true that you CAN use
LVM to do some sort of striping... you don't have to. In which case
LVM just becomes a way of creating flexible volumes.
>
> Rhel 4.4 installed lvm by default, even though the system is installed on a
> hardware raid mirror. Should I (and can I) un-lvm the system disk?
>
> I installed additional disks and created a second hardware-based raid
> mirror. Is there any reason to use lvm on it, or just plain old ext3?

LVM is NOT a filesystem. LVM allows you to abstract disks into logical
volume groups and logical volumes (the latter usually will have a
filesystem like ext3 on it).
>
> -Frank
> http://www.inwa.net/~frog/
>
>

Re: lvm and hardware raid?

Frank -

LVM introduces a level of complexity to disk management that is of
questionable value to admins of small to medium-sized systems. Not
that I'm suggesting your project meets that description. I can tell
you from experience, though, that recovering a corrupted filesystem
from an LVM volume is not the same deal as Ye Old Waye of Doing
Things. A search on "LVM recovery" tells the story. Linux Journal had
a good article on the subject this year, I think. While I can see the
value of LVM, I rest more comfortably having set up my partitions on a
good battery-backed hardware RAID with the assistance of our old pal
Fdisk. If I were doing multiple terabytes of storage on a rapidly
growing system, my opinion might be different.

TL

On Thu, 12 Oct 2006 16:02:12 GMT, "frank"
wrote:
>Is there any reason to use lvm on a server with a hardware raid controller?
>Wouldn't using lvm be redundant and introduce additional overhead?
>
>Rhel 4.4 installed lvm by default, even though the system is installed on a
>hardware raid mirror. Should I (and can I) un-lvm the system disk?
>
>I installed additional disks and created a second hardware-based raid
>mirror. Is there any reason to use lvm on it, or just plain old ext3?
>
>-Frank
>http://www.inwa.net/~frog/
>